<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<style>
    .div1 {
        width: 300px;
        height: 300px;
        background: #84ff9d;
    }
</style>
<body>
<button>按钮</button>
<div class="div1">1</div>
<script>
    var btn = document.querySelector('button');
    btn.addEventListener('click',function () {
        alert('777');
    });
    btn.addEventListener('click',function () {
        alert('666');
    });
    var div1 = document.querySelector('.div1');
    div1.addEventListener('click',fun1);
    function fun1() {
        alert('666666');
        div1.removeEventListener('click',fun1)
    }
</script>
</body>
</html>